Texas Instruments TL16C552AIFNG4

Overview

TL16C552AIFNG4 from Texas Instruments is a dual-channel UART with integrated 16-byte FIFOs per channel and a bidirectional Centronics-compatible parallel printer port, operating at up to 8 MHz clock input and supporting 5–8-bit character framing, even/odd/no parity, and 1/1.5/2 stop bits. It serves as a single-chip I/O solution for IBM PC/AT-compatible systems requiring simultaneous serial and parallel interface management.

For engineers reviewing the TL16C552AIFNG4 datasheet, TL16C552AIFNG4 pinout, TL16C552AIFNG4 application, or TL16C552AIFNG4 equivalent, this device delivers deterministic interrupt handling (INT0/INT1/INT2), independent modem control per channel (RTS/DTR/CTS/DSR/DCD/RI), hardware/software compatibility with TL16C452, and 5 V ±5% supply operation in industrial temperature range (0°C to 70°C).

Technical Context

The TL16C552AIFNG4 integrates two independent TL16C550 ACEs sharing a common 8-bit CPU bus interface and address decoding (A0–A2), each with programmable baud rate generation (divisor 1–65535), 16-byte receive/transmit FIFOs, and full modem status/control register sets (MSR/MCR). Its parallel port implements all Centronics handshaking signals (STB, ACK, BUSY, PE, SLCT, AFD, INIT, ERR) with open-drain outputs and internal ~10 kΩ pullups on INIT, AFD, STB, and SLIN.

Interrupt architecture supports three independent outputs: INT0 and INT1 for serial channel events (RX/TX/error/modem), and INT2 for parallel port (ACK-triggered or PRINT-sourced, selectable via ENIRQ), with configurable priority and masking per channel via IER registers. All I/O terminals are TTL-compatible with 3-state bus drivers (DB0–DB7, PD0–PD7) and CMOS-level inputs (TRI, RESET, CLK).

Key Specifications

Pinout & Package

TL16C552AIFNG4 is housed in a 68-pin plastic leaded chip carrier (PLCC, FN package), with leads arranged in a square perimeter and pin 1 marked by a corner notch. The package is RoHS-compliant and designed for reflow soldering on standard PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual UART + parallel port applications.

Compared with TL16C552AFN, TL16C552AIFNG4 offers identical electrical and functional behavior with added RoHS compliance, while SC16C552B provides voltage flexibility at the cost of mechanical and pinout incompatibility - making TL16C552AIFNG4 the optimal choice for lead-free PC/AT and industrial retrofits.

Availability

TL16C552AIFNG4 is available at Aetrix Electronics and suitable for IBM PC/AT-compatible system upgrades, industrial serial terminal controllers, and embedded communication gateways requiring stable component supply and long-term lifecycle support.

Supply support for TL16C552AIFNG4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader founded in 1930, specializing in analog, embedded processing, and connectivity technologies with broad industrial, automotive, and communications product portfolios.

The TL16C552AIFNG4 belongs to TI's legacy communications interface family, designed specifically to consolidate dual UART and parallel printer functionality into a single IC for IBM PC/AT and industrial host systems requiring reliable, low-interrupt serial I/O.

FAQ

What is the maximum baud rate supported by the TL16C552AIFNG4?

The TL16C552AIFNG4 supports a maximum baud rate determined by its 8 MHz clock input and 16-bit divisor (1–65535). With divisor = 1, the theoretical maximum is 4 Mbps (8 MHz / 2), but practical RS-232 limits and timing margins constrain typical use to ≤1.8432 Mbps. Actual achievable rate depends on line loading, cable length, and receiver tolerance - always verify with oscilloscope measurement of SOUT edge timing.

Does the TL16C552AIFNG4 support 3.3 V operation?

No, the TL16C552AIFNG4 is strictly a 5 V device with recommended supply range of 4.75 V to 5.25 V. Its I/O structure is TTL-compatible, not 3.3 V tolerant: inputs require ≥2 V for high recognition, and outputs drive ≥2.4 V high at −0.4 mA. Direct connection to 3.3 V logic without level translation risks damage or unreliable operation.

How does the TL16C552AIFNG4 handle interrupt prioritization between its two UART channels and parallel port?

The TL16C552AIFNG4 provides three physically separate interrupt outputs - INT0 for channel 1, INT1 for channel 2, and INT2 for the parallel port - allowing external logic or CPU interrupt controllers to assign independent priority levels. Within each UART, interrupt sources (RX ready, TX empty, line error, modem change) are masked individually via the IER register, enabling fine-grained control without software polling.

Can the parallel port on the TL16C552AIFNG4 be used for general-purpose I/O instead of printer control?

Yes, the PD0–PD7 lines function as a bidirectional 8-bit port. When PEMD is high, the DIR bit in the parallel port control register sets direction per nibble; when PEMD is low (default for printer mode), writes to the data register drive outputs directly. This allows use as GPIO for status signaling, sensor interfacing, or LED control - provided handshaking signals (STB, ACK, etc.) are disconnected or ignored.

Is the TL16C552AIFNG4 pin-compatible with the TL16C452?

Yes, the TL16C552AIFNG4 is hardware and software compatible with the TL16C452, sharing identical pinout, register map, and bus timing. It extends the TL16C452 by adding 16-byte FIFOs per channel and enhanced interrupt control - enabling drop-in replacement in existing TL16C452 designs to reduce CPU interrupt load without modifying PCB layout or firmware initialization sequences.